Measurements of the production of open-heavy flavour hadrons in heavy-ion collisions provide important information on the properties of the Quark–Gluon Plasma (QGP), the state of strongly-interacting matter formed at the very high temperatures and energy densities reached in heavy-ion collisions [1]}, [2]}.
Several measurements of the production and elliptic flow of D mesons and leptons from the decay of heavy-flavour hadrons in \(\mbox{Pb--Pb}\)  collisions at the LHC and in \(\mbox{Au--Au}\)  collisions at RHIC [3]}, [4]} indicate that charm quarks interact strongly with the medium constituents. In-medium energy loss is studied via the nuclear modification factor, \(R_{\rm AA}\) , defined as the ratio of the yield in \(\mbox{Pb--Pb}\)  collisions and that in \(\mathrm {p\hspace{-0.50003pt}p}\) collisions scaled by the number of binary nucleon–nucleon collisions.
A model [5]}, [6]} including a significant fraction of low and intermediate transverse momentum (\(p_{\rm T}\) ) charm and beauty quarks hadronising via coalescence (or recombination) with light quarks from the medium better describes the experimental results.
This mechanism is expected to also affect the production of \({\rm D_s^+}\)  given the strange-quark rich environment of the created medium. At higher transverse momentum (\(p_{\rm T}\)  \(>7\)  GeV/\(c\)  at LHC energies [7]}) hadronisation by vacuum fragmentation is expected to be the dominant production mechanism.
